Re: [PATCH 10/21] q800: add easc bool machine class property to switch between ASC and EASC

[Philippe Mathieu-Daudé]

On 8/9/23 08:54, Mark Cave-Ayland wrote:
> On 07/07/2023 09:29, Philippe Mathieu-Daudé wrote:
>
> > On 2/7/23 17:48, Mark Cave-Ayland wrote:
> > > This determines whether the Apple Sound Chip (ASC) is set to enhanced 
> > > mode
> > > (default) or to original mode. The real Q800 hardware used an EASC 
> > > chip however
> > > a lot of older software only works with the older ASC chip.
> > >
> > > Adding this as a machine parameter allows QEMU to be used as an 
> > > developer aid
> > > for testing and migrating code from ASC to EASC.
> > >
> > > Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> > > ---
> > >   hw/m68k/q800.c         | 30 +++++++++++++++++++++++++++++-
> > >   include/hw/m68k/q800.h |  1 +
> > >   2 files changed, 30 insertions(+), 1 deletion(-)
> >
> >
> > > +static bool q800_get_easc(Object *obj, Error **errp)
> > > +{
> > > +    Q800MachineState *ms = Q800_MACHINE(obj);
> > > +
> > > +    return ms->easc;
> > > +}
> >
> > Is the getter useful? Otherwise:
>
> Isn't it a requirement? Otherwise I can see that if we decide to 
> enumerate machine properties (similar as to how device properties appear 
> in "info qtree") then it would be impossible to display its value. 
> Certainly at the moment we consider that adding an object property to an 
> underlying struct effectively makes it "public".

Just FYI this is not a requirement, per "qom/object.h":

  /**
   * object_property_add_bool:
   * @obj: the object to add a property to
   * @name: the name of the property
   * @get: the getter or NULL if the property is write-only.
   * @set: the setter or NULL if the property is read-only

I'm not sure when we want a write-only QOM boolean property, so I
genuinely ask, since I agree introspecting QOM object fields from
the monitor is helpful.

Regards,

Phil.